Means for positioning remote objects



May 17, 1932.

B. A. WITTKUHNS MEANS FOR POSITIONING REMOTE OBJECTS Filed Oct. 11. 1930Patented May 17, 1932 UNITED. STATES PATENT orri'cs ammo a. wrr'rxurms,or cmrmmnnw many, ASSIGNOR 'ro srnnar ornoscorn COHPANY, rumor naoonam,NEW YORK, a ooaroaa'rron or NEW YORK mus FOR POSITIONING REMOTE OBJECTSApplication filed October 11, 1930. Serial li'o. 488,051.

' This invention relates to self-synhronous remote control ortransmission systems, especially to systems which areadapted to exert aprecia le torque on the controlled object. rent ty' having a thermionicamplifier between t e sending instrumentand the receiving instrument bywhich a power; motor is controlled as to torque and direction for turn-Y 1 ing the driven object. M system, thereforei is to be distinguishedom the so-calle Selsyn self-synchronous system which is unada ted forturning heavy objects unless anad 'tional power motor'is employedbesides the transmitter and repeater motor.

Referring to the drawings, Fig.1 is awiring diagram illustrating myinvention as applied to the vremote control of an object such as asearchlight. 30 Fig. 2 is a vector diagram of the E. M. Fs. generated inthesending and receiving coils. Fig. 3 is a side elevation of a modifiedform of sendin instrument.

According to my invention I continuously generate opposing A. C.potentials by the relative rotation of magnetlc poles and windings. Asshown I rotate one or more pole pieces or permanent magnets 1-2 at thesending instrument and similar, permanent 80 ma ets 3-4 at the receiver..Both magnetlc units are rotated continuously at the same speed,preferably by synchronous A. O. i motors 5-6 driven from the polyphas'esu ply S. Surroundin or in the magnetic fielll 85 of the pole pieces ofth sender and receiver are similar coils or windings 7-8. The two coilsare shown as provided with suitable indicating dials 13-14 and thesending instrument is also provided withany suitable means for turninthe'same, such as the knob 15. A searchlig t is diagrammatically reresented as turned from dial 14. As the po e ieces are rotatedalternating potentials will generated inboth coils. Preferably 4 thecoils are connected in opposition so that when they are Slmillllilglaced with respect to the poles, the E. s. generated will be equal and180 out of phase as illustrated by the arrows E and E in Fig. 2. If,however, coil 7 at the sending instrument 1s disy system is of thealternating curplaced slightly from said 'position (or the relationbetween the revolving poles on the sender and receiver are disturbed)the phase of the generated E. M. Fs will be dlsplaced to the rightorjleft, depending on the direction of the displacement of the coil asillustrated by the dotted arrows F and F of Fig; 2. This will give riseto a definite unbalanced potential .P or P I make sure of thisunbalanced potential to operate. a servo motor 10 at the receiver whichis shown as geared through reduction earin 11-12 to rotate the coil 8 soas to ring 1t into parallelism with coil 7.

For actuating the servo motor upon minute changes in the positionbetween the sending and receiving instruments, I prefer to em 10y athermionic am lifying system in which the grid 16 of the rst tube 17 isconnected in circuit with the opposing coils 7 and 8. The particularform of amplifier which I preferto use and which is shown in thedrawings is described in detail and.

claimed in my copending application, Serial No. 433,562, filed March 6,1930 for remote control systems.

According to my invention, all the current for the resistors, motors andamplifying unit is furnished from a common polyphase supply, no othersource of current being necessary. For supplying current of the propervoltage and phase relation I have shown a pair of transformers 25 and26, the former being used to su ply plate potentials to the push-pulla-mpli er 18 and the latter supplymg the heating current for the tubes.As shown, the filament of the first tube is heated by secondary winding26' of the transformer 26. The output of the first tube passes throughthe inter-stage transformer 40 and thence to a pair of 'power tubes 18arranged in push-pull fashion. These tubes have their filaments lightedfrom the secondary 26" of transformer 26 and alternatin current ofopposite potential is sup lied to t e plates thereof by connecting sa1plates to the opposite ends of the secondary 25' of the transformer 25.The grid bias for these tubes may be obtained by connecting the grids tothe center tap 41 on the wind ng 25 er, an analysis will show that thecurrent flowing through the resistor will be pulsating direct currentwhich may be smoothed out by condensers 43 in a well known manner. Ialso connect to said resistor, preferably at an intermediate point 44,the mld point/ of the winding 26.- The resistor 27 thus completes acircuit through the first tube as well as the others and by connectingthe grid of the first tube to an intermediate point 46 on the resistor,the id bias for this tube may be obtained. a A eed-back coupling is thusalso bbtained throughthe re sistor. 'Also the, proper D. C. platepotential is obtained from the same resistor by an intermediate tap 47connected through transformer to the plate of the first tube. The finaloutput of the tubes is led through the output transformer 19. Thistransformer has two primaries 4849 connected respectively between theplates of the two tubes 18 and the secondary2'5' of transformer 25. Thesecondary' of said transformer has a center tap cross connected togacenter tap on the primary of transformer'25 thus forming a Scottconnection by which two phases are supplied tothe motor 10, the thirdphase bein supplied directl from the third phase of t e supply line. heresult is that two of the phases of the motor 10 will be reversedwhenever. the direction of movement of the coil? is reversed indirection thus causing the respect to the armature or le motor 10-todrive the card14 and coil 8 in the proper direction to restoresynchronism between the same and the card 13 and coil 7.

It will be understood that the proper phase relations are obtainedthrough the proper design and adjustment of resistance, capac ity andinductance in the system. My stem is thus wholl operable from the pophase su ply and by it alarge torque may l ie produce at the receiverand at the same time complete synchronism and" high' accuracy obtained.r r

Electrically speaking, it is, of course, im-' material whether-the coil7 is shifted with ieces 1-2 or whether the rotation of 21110 e pieces isslightl advanced or retard .1 A sim 1e method of 'e'fiecting theinvention by the tter method is illustrated in Fig. 3. According to'thisfigure, the synchronous motor 5' \is rotatably mounted on thetbracket 81so that the field of the motor may be adjusted as byturningc'rank 32which turns the irre vers1ble-,'worm 38meshing with the wormwheel 34secured'to. the field casing of the motor, Also secured to said casingis the card 18. 7 The ole pieces Land 2 are secured to the shaft of themotor as before,

sider to represent t but in this case the coil 7' may be fixed to theframe 31. :It is obvious that the receiver means. Also, while it isdesigned to use the various features and-elements in the combination andrelations described, some of these may be altered'and others omittedwithout interfering with the more general results outlined, and theinvention extends to such use.

-Having described my invention, what I claim and desire to secure byLetters Patent is:

1. 'In a self-synchrondus remote control system, a two-part transmittercom risin rotatable pole pieces,-a rotatable winding a jacent saidpoles, means for continuously relatively rotating one of said arts, andmeans for turningv the other of said parts to any desired position, atwo-part receiver havsimilar poles and winding, means for re ativelyrotating one of said parts driven from the same supply as said firstmentioned rotating means, a reversible motor for rotating theiother ofsaid parts,'and an amplificaand motor for controlling the movements ofsaid motor.

l 2. In itself-synchronous remote-control and a thermionic circuit incircuit between said windings andlnotor and powered by said supply .forthe movements ofsaidmotor.-

3. A self-synchronous remote control system as claimed in claim2-wherein athreephase-supply is employed and a three-phase reversiblemotor, the latter ha ceiver producing A. C." of like frequency, meansfor rotating the same in synchrcnism with the transmitter, means fordisplacing one base -thereof excited from said an p y .an two 1 tioncircuit in circuit between said windings no the normal phaserelationship between the armature and field of the transmitter, a poweramplifier controlled by the resultant E. M. F. produced by such phasedisplacement, and 5 a reversible motor connected to the receiver andcontrolled from the output of the amplifier for displacing therecelverto maintain synchronism with the transmitter. 5. In a self-synchronousremote control system, a continuously rotated generatortransmitterhavingan armature and field and producing A. (1., a similargenerator-receiver producing A. C. of like fre uency, synchronous motorsfor rotating oth generators 4 t synchronously, an .A. C. supply for saidmotors, means for displacing the normal relationship between thearmature and field of the transmitter, a power amplifier controlled bithe resultant E. M. F. produced by such p ase displacement and poweredfrom said supply, and a reversible motor connected to the receiver andcontrolled from the output of the amplifier and said supply fordisplacin' the receiver to maintain synchronism with t e transmitter.

' 6-. In a self-synchronous remote control system, a transmitter havinga rotor member comprising magnetized, pole pieces and a stator membercomprising rotatable wind- 3o ings, rotating means for providingcontinuous constant speed relative motion between stator and rotor,means for changing the rate of said relative motion to any desired adegree or position, a receiver having a similar stator and rotorandsimilar means for providin the same continuous constant speed reative motion between stator and rotor driven from the same supply assaid first-mentioned means, a reversible motor for changing the rate ofsaid relative motion, and an amplifier controlled b the differentialoutput of the windings o the transmitter and receiver for operating saidmotor In testimony whereof I have aifixed my sig ature. 1 W a W BRUNO A.WITTKUHNS.

